Upon quitting the marbles to pass on to the other more remarkable stones, who can for a moment doubt that the magnet will be the first to suggest itself? For what, in fact, is there endowed with more marvellous properties than this?[2]

We know that the lodestone has a wonderful power of attracting iron. When I first saw it I was thunderstruck, for I saw an iron ring attracted and suspended by the stone; and then, as if it had communicated its own property to the iron it attracted, and had made it a substance like itself, this ring was put near another, and lifted it up; and as the first ring clung to the magnet, so did the second ring to the first. A third and a fourth were similarly added, so that there hung from the stone a kind of chain of rings, with their hoops connected, not interlinking, but attached together by their outer surface. Who would not be amazed at this virtue of the stone, subsisting as it does not only in itself, but transmitted through so many suspended rings, and binding them together by invisible links?

It is inconceivable that inanimate brute Matter, should, without the mediation of something else, which is not material, operate on and affect other Matter without mutual Contact, as it must be, if Gravitation in the sense of Epicurus, be essential and inherent in it. And this is one Reason why I desired you would not ascribe innate Gravity to me. That Gravity should be innate, inherent and essential to Matter so that one Body may act upon another at a Distance thro' a Vacuum, without the Mediation of any thing else, by and through which their Action and Force may be conveyed, from one to another, is to me so great an Absurdity, that I believe that no Man who has in philosophical Matters a competent Faculty of thinking, can ever fall into it. Gravity must be caused by an Agent acting constantly according to certain Laws; but whether this Agent be material or immaterial, I have left for the Consideration of my Readers.[5]

As I wrote in a previous article (Depletion Attraction, March 7, 2011), even non-fundamental forces can be mysterious. There's an unusual attractive force between large particles called depletion attraction when they're in solution with smaller particles. Since two particles in solution can't occupy the same space at the same time, and one large particle can take the place of many smaller particles, surface effects become important, and the many small spheres filling the same volume as one larger sphere will have a larger surface area exposed to the solution.

"It's hard to find a scenario where this force would stand out... It is not clear it makes a significant effect anywhere. Yet... People think blackbody radiation is a classical concept in physics - it was a catalyst for starting the quantum mechanical revolution 100 years ago - but there are still cool things to learn about it."[9]